Test 4 Flashcards
Is metabolism the process by which your body converts food into energy?
Yes
Does metabolism include all the chemical reactions in your body that keep you alive?
Yes
What is the difference between catabolic and anabolic pathways?
Catabolic: Break down large molecules into smaller ones, releasing energy. Anabolic: Processes that build up large molecules from smaller ones and use energy
Define free energy
A system that is available to do work
What is the difference between an exergonic reaction and an endergonic reaction?
Exergonic: chemical reaction that releases energy and happens on its own without needing extra. Endergonic: chemical reaction that absorbs energy and needs energy to happen
In what reactions can a positive/negative free energy value be found?
Positive: endergonic reactions. Negative: exergonic reactions.
What is the general equation of aerobic respiration?
Glucose + Oxygen to Carbon dioxide + Water + Energy (ATP) (C6H12O6 + O2 to CO2 + H20 + Energy (ATP))
What is the first step of aerobic respiration?
Begins with glycolysis which occurs in the cytoplasm. This is where one molecule of glucose is broken down into two molecules of pyruvate
What does the break down of one molecule of glucose into two molecules of pyruvate create?
A net gain of 2 ATP and 2 NADH molecules
What happens next in the oxidation of pyruvate in the mitochondrial matrix?
Each pyruvate is converted into acetyl CoA, releasing one NADH per pyruvate
What happens in the Krebs cycle (citric acid cycle)?
Acetyl CoA is fully oxidised, releasing two molecules of CO2 per cycle
What does the Krebs cycle generate?
2ATP, 6NADH, and 2FADH2 per glucose
Where are the high energy electrons from NADH and FADH2 passed to?
The electron transport chain in the inner mitochondrial membrane
Does the energy in the electron transport chain then pump protons across the membrane, creating a proton gradient?
Yes
What is the final electron accepter?
Oxygen, forming water
What does the proton gradient drive, and how many ATP molecules does ATP synthase produce at chemiosmosis?
Chemiosmosis. 26-28.
How much ATP is produced in glycolysis, oxidation of pyruvate to acetyl CoA, and Krebs cycle respectively?
Glycolysis: 2, oxidation of pyruvate to acetyl CoA: 0, and Krebs cycle: 2
How does DNP affect chemiosmosis?
Disrupts it by making the inner mitochondrial membrane leaky to protons
What does disrupting chemiosmosis prevent?
Prevents the proton gradient from being used efficiently by ATP synthase to make ATP
Does energy get released as heat instead?
Yes
Define electron carriers
Transport electrons during cellular processes. Common electron carriers include NADH and FADH2
What does being oxidised and reduced mean?
Oxidised: accepts electrons and a hydrogen ion to become reduced. Reduced: carries electrons to the electron transport chain
What are the oxidised forms of the major electron carriers?
NAD+, FAD
What are the reduced forms of the major electron carriers?
NADH, FADH2
What is the general equation of photosynthesis?
Carbon dioxide + Water + Light energy to Glucose + Oxygen (CO2 +H20 + Light energy to C6H12O6 +O2)
What are the two main stages photosynthesis consists of?
Light-dependent, and light independent reactions (Calvin cycle)
Where do light dependent reactions happen?
In the thylakoid membranes of the chloroplasts
When chlorophyl absorbs light energy, where do electrons get passed through and what does this lead to?
Through the electron transport chain, and to the production of ATP and NADPH
Do water molecules split during this process, replacing the lost electrons, and releasing O2 as a byproduct?
Yes
Where do light independent reactions occur?
In the stroma of the chloroplasts (the fluid surrounding the thylakoids)
What do light-independent reactions depend on if it is not light directly?
The ATP and NADPH produced in the light-dependent reactions
Describe the Calvin cycle
CO2 from the atmosphere which is fixed to a 5-carbon molecule is broken down into two molecules of 3-PGA. This is then converted into a three carbon sugar, after which some exit the cycle to form glucose and other carbs, while others are recycled
What are the some of the key products of Calvin cycle?
NADP+ and ADP, which return to the light-dependent reactions to be recharged
What kind of reactions are photosystem II and photosystem I both crucial components of?
Light dependent reactions of photosynthesis
What do all photosystems help to accomplish?
Capture light energy and facilitate the production of energy-rich molecules like ATP and NADPH
What is PSII responsible for?
The initial step of absorbing light energy and using it to split water molecules into oxygen, protons (H+), and electrons. Also helps produce ATP by creating a proton gradient
What is PSI’s function?
Absorb light energy and use it to re-energise the electrons that have passed through the electron transport chain
Are these high energy electrons then transferred to NADP+, reducing it to NADPH?
Yes
What is Rubisco?
An enzyme that is essential for turning CO2 from the air into organic compounds that plants can use
Define metabolic pathway
A series of chemical reactions that happen inside a cell, that help a cell get energy, build things it needs, and break things down
What are the two ways ATP is formed?
Substrate-level phosphorylation (occurs in glycolysis and the citric acid cycle), and oxidative phosphorylation (occurs in electron transport and chemiosmosis)
